Mechanical conditioning by bead blasting lithium iodine cell case

ABSTRACT

Bead blasting the inner, contact surface of an electrochemical cell casing to render the inner surface thereof essentially contamination free and suitable as a current collector is described. The casing is preferably of stainless steel and houses the alkali metal-halogen couple in a case-positive configuration.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. application Ser. No.13/340,217, filed on Dec. 29, 2011, now U.S. Pat. No. 9,293,741, whichclaims priority from U.S. provisional application Ser. No. 61/427,924,filed on Dec. 29, 2010.

BACKGROUND OF THE INVENTION

The present invention generally relates to a solid-state primary cell,and more particularly, to improved discharge performance for alkalimetal-halogen cells with simplified methods of making the same. Thecells are preferably housed inside of stainless steel cases and theimprovements are realized by mechanically conditioning the insidesurface of the case according to the present invention prior tointroduction of the cell active components.

PRIOR ART

The condition of the internal surface of the stainless steel casingsemployed in lithium/halogen cells, particularly lithium/iodine cells,has been determined to be critical to cell electrical performance. Inmany case-positive cell designs, the casing inner surface or wall servesas the cathodic current collector, facilitating electron transfer duringdischarge. Voltage, impedance and delivered capacity at low currentdrains can all be adversely affected by contaminants which may bepresent on casings in their condition as received from suppliers.

Conventional practice in the preparation of the cell casing used inconstruction of alkali metal-halogen cells is to first acid treat thecase to remove surface contamination. One such method of removingsurface contamination is by using a chemical etchant. One such chemicaletchant is sold under the trade name of Diversey®. These chemicaletchants typically comprise a strong acid that reacts with the surfaceremoving a layer of the surface, thereby removing surface contaminationthereof.

In such chemical etchant treatments, the stainless steel case forexample, is dipped in the chemical etchant. These chemical etchanttreatments are generally effective, but it is a time-consuming andincreasingly expensive process. Approximately three percent of theweight of each case is removed, dissolved in the acid along with anysurface contaminants also present. Thus, bath life becomes limited dueto the increasing concentration of metal ions in the costly, strong acidsolution with use. As a result, over time, the chemical etchant bathbecomes less effective, thereby creating cell case surface conditionsthat are not uniform. These non-uniform surface condition areas therebyproduce electrochemical cells with inconsistent electrical performance,particularly that of output voltage.

In addition, the total chemical etchant process requires two activepretreatment steps, along with copious rinsing and final solvent drying.The acid dipping process is labor-intensive and time consuming. Finally,environmentally sound disposal of the heavy metal-laden spent acid andrinse wastes is becoming prohibitively expensive.

Alternative to chemical etching, electro-polishing methods have alsobeen utilized to remove contamination from the surface of cell cases. Inthe electro-polishing process, the surface of the cell case is typicallysubjected to a sequence of pre and post polishing steps. The pretreatment preparation process often comprises a vapor degreasing step,an acid pickling step and a series of rinses. After the surface issubjected to the pre treatment process, the surface is thenelectro-polished. The electro-polish process generally involvessubmersion of the surface in an electrically charged acid bath comprisedof various acids and electrical parameters. After the surface iselectro-polished, the surface is then subjected to a post polishingprocess typically comprising a series of rinses and drying steps but mayalso include an additional chemical treatment sequence.

Similar to the chemical etchant process, as described before,electro-polishing is a time-consuming and increasingly expensiveprocess. Like the chemical etchant process, electro-polishing is anextensive and complex process that requires costly equipment andchemicals to perform. In addition, electro-polishing methods areprimarily chemical reaction driven processes in which theelectro-polishing chemicals become limited due to the increasingconcentration of metal ions that accumulate in the acid solution withuse. As a result, over time, the electro-polishing bath becomes lesseffective thereby creating cell case surface conditions that are notuniform and therefore produce cells with inconsistent electricalperformance.

There is, therefore, a need for a casing, preferably a stainless steelcase, for an alkali metal-halogen cell wherein the casing inner surfaceis essentially free of contaminants to ensure satisfactory electricalperformance during discharge. The alkali metal-halogen electrochemicalcouple is typically constructed in a case-positive configuration withthe case wall serving as the cathodic current collector. A contaminationfree inner surface for the casing facilitates electron transfer duringdischarge. It would, therefore, be highly desirable to provide theforegoing in a time-saving, economical and environmentally sound manner.

SUMMARY OF THE INVENTION

The present invention is directed to conditioning the inner surface ofelectrochemical cell cases through a bead blasting process. During thebead blasting process, a pressurized stream of discrete beads composedeither of metal, ceramic or glass, is directed at a surface of the cellcase. The beads impinge the surface, particularly the inner surface, ofthe electrochemical cell case thereby removing undesirable surfacecontamination. In addition to removing surface contamination,impingement of the beads on the surface of the case increases theoverall surface area of the case surface, thereby increasing the surfacearea of the current collector of the cell. The bead blasting process iscarried out on cell cases in the as-annealed condition received fromsuppliers without the need for pretreatment of any kind. The cell casesare preferably of stainless steel and are used to construct alkalimetal-halogen cells of the central anode, case-positive configuration.The bead blasted cases are ready for cell assembly after a final rinseand cell electrical performance is maintained without the need for wetchemical treatment. A preferred electrochemical system is thelithium-iodine couple.

According to the present invention, the lithium-iodine couple is housedin a bead blast conditioned casing and comprises a lithium anode, asolid-state lithium halide electrolyte, and a solid-state electronicallyconductive cathode that contains iodine. The anode reaction is:Li→Li⁺ +e−and the cathode reaction is:I₂+2e ⁻→2I⁻giving an overall reaction of:2Li+I₂→2LiI

This electrochemical system is especially advantageous in that lithiumhas a high energy density, as the most electropositive metal with thelowest equivalent weight. The electrolyte formed on discharge of thecell is LiI. This lithium salt has the highest ionic conductivity, muchhigher than the ionic conductivity of divalent halides.

The cathode iodine may be free iodine intimately admixed with a solidelectronic conductor or, preferably, it is at least partially chemicallybound as in organic-iodine charge transfer complexes. The electrolyte ispreferably lithium iodide, which may be formed in situ by contacting theanode and cathode surfaces, whereby lithium reacts with iodine in thecathode to form a solid lithium iodide electrolyte layer contacting theanode and cathode. Alternatively, the electrolyte includes a coating oflithium iodide or other lithium halide on the lithium anode formed byreaction of the lithium with iodine or another halogen. The cathode iscontacted against the inner surface of the bead blasted casing, whichserves as the cathode current collector.

Lithium-iodine cells fabricated in casings that have been treatedaccording to the present invention have a high operating voltage,typically an open circuit voltage of about 2.7 to 2.8 volts, dependingprimarily on cell design and the cathode material. Testing has revealedthat the prior art processing methods of chemical etching andelectro-polishing yield lithium-iodine cells with a more varied voltageoutput as compared to the method of the present invention. Specifically,test results show that the voltage output of cells produced with theprior art methods can vary as much as 56 millivolts as compared to about13 millivolts for cells produced with the method of the presentinvention. This is an improvement of over 75 percent in manufacturingrepeatability from cell to cell. This improvement is believed to beattributed to not only the removal of surface contamination andresistive oxide layers, but also to the increased surface area resultsfrom the method of the present invention.

Such an improvement in the manufacturing process is beneficial inreducing manufacturing costs. In addition, the improvement in electricalperformance of these cells is particularly beneficial in that they aredesigned to power medical devices that demand exacting electricalperformance time after time. Thus, the present invention is an improvedmanufacturing process for this electrochemical couple that increaseselectrical performance repeatability without compromising dischargeefficiency.

The above aspects of the present invention will become more apparent tothose skilled in the art by reference to the following description andto the following drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an exemplary alkali metal-halogen cell10 housed in a bead blast conditioned casing 12 according to the presentinvention.

FIG. 2 is an enlarged sectional view taken about on line 2-2 in FIG. 1.

FIG. 3 illustrates a perspective view of an embodiment of casings of thealkali metal-halogen cell 10 in an as received condition.

FIG. 4 illustrates a perspective view of an embodiment of a fixture usedto hold the casings 12 during the bead blasting process.

FIG. 5 shows a perspective view of an embodiment of the casings 12 beingbead blasted according to the method of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIGS. 1 and 2, there is shown an exemplary alkalimetal-halogen electrochemical cell 10 housed inside of a casing 12 inwhich its surface has been conditioned through a bead blasting treatmentaccording to the present invention. The casing 12 is of a metal such asstainless steel and includes spaced apart sidewalls 14, 16 joined bycurved end walls 18, 20 and a curved bottom wall 22. Although stainlesssteel is the preferred casing material, it is contemplated that othermaterials such as titanium, mild steel, nickel plated steel, aluminum,or nickel cobalt alloys may be used. In accordance with the presentinvention, prior to assembly of the cell 10, the casing 12 is beadblasted for a period of time sufficient to render the inner surface 24of the casing essentially free of contaminants to ensure satisfactoryelectrical performance of the cell during discharge. According to apreferred aspect of the present invention, the casing 12 is subjected toa pressurized stream of beads for about 2 to about 10 seconds. In apreferred embodiment, a pressure from about 0.34 MPa (50 psi) to about0.48 MPa (70 psi) may be used. The composition of the beads isnon-limiting and may comprise a metal, a ceramic material such asalumina or zirconia, or a glass. In a preferred embodiment, glass beadshaving a grain size from about 35 μm to about 65 μm, per MIL SPEC“G”—9954A are used during the bead blasting process. The conditionedcasing is ready for cell assembly after a final rinse in deionizedwater.

As shown in FIG. 3, casings 12, in an as received condition, arepositioned in a bead-blasting fixture 60. The fixture 60, as shown inFIG. 4, comprises a fixture lid 62, a fixture base plate 64 and left andright fixture sidewalls 66, 68 positioned therebetween. The fixturesidewalls 66, 68 serve as support structures between the lid 62 and baseplate 64.

The fixture base plate 64 comprises a series of openings 70 that extendwidthwise along the length of the lid 62. Each of the series of openings70 extends through the thickness of the base plate 64. Furthermore, eachof the openings 70 has a recess 72 with an annular lip 74. The fixtureopenings 70 are designed such that the annular lip 74 of the openings 70align with a case rim 76 that surrounds the opening 78 of the cell case12 (FIG. 3). When the cases 12 are correctly positioned within thefixture 60, as shown in FIG. 5, the fixture openings 70 providerespective passageways that communicate with the case opening 78 to theinner surface 24 of the case 12.

After each of the as received cases 12 is positioned within the fixture60, the lid 62 is placed across the left and right sidewalls 66, 68,enclosing the cases 12 therewithin. A spacer 80 preferably composed of asoft material such as foam or rubber is attached to the bottom surfaceof the fixture lid 62. The spacer 80 provides a cushion between thebottom of the fixture lid 62 and curved casing bottom wall 22 andensures a snug fit therebetween. Alignment pins 82 extend from a topsurface of the left and right sidewalls 66, 68. These pins 82 arepositioned within lid openings 84. A wing nut 86 is preferablypositioned through fixture slot 88 and is secured down within each ofthe fixture sidewalls 66, 68 enclosing the cases 12 therewithin.

Once the as received cases 12 are secured within the fixture 60, thecases are ready to be bead blasted. As illustrated in FIG. 5, apressurized stream of beads 90 is directed towards the openings 70 ofthe fixture 60. The stream of beads 90 exits a bead-blasting nozzle 92and passes through the fixture opening 70, entering the case opening 78and contacting the inner surface 24 of the case 12. In a preferredembodiment, the stream of beads 90 impinges on the inner surface 24 ofthe case 12, thereby removing any surface contamination thereof. Inaddition, bombardment of the beads against the inner surface 24 of thecase 12 roughens the surface, thereby increasing its surface area.Therefore, by increasing the surface area of the inner surface 24 of thecase 12, the surface area of the cathode current collector of the cellis increased, thus increasing the chemical reaction rate within the cell10. After about 2 to 5 seconds of exposure, the stream of beads 90 isdirected to the next opening 70 and cell case 12. This process isrepeated until each of the cell cases 12 within the fixture 60 isconditioned with the pressurized stream of beads 90. After each of thecases 12 has been bead blasted, they are then rinsed and dried.

The electrochemical cell 10 housed inside of the bead blasted casing 12includes an anode, generally designated 26 and comprising alkali metal,preferably in the form of a pair of lithium plates 28, 30 pressedtogether and bonded against an anode current collector 32. The anodecurrent collector 32 is a portion of the anode conductor means of thecell. Anode current collector 32 thus is sandwiched between plates 28,30 and can be of various forms such as a length of wire, a strand orribbon, or a mesh or screen. Anode current collector 32 is of metal suchas nickel or nickel alloy. Each of the lithium plates 28, 30 in the cellof FIG. 2 has generally planar, oppositely directed parallel surfaces.Lithium plate 28 is identical to lithium plate 30 in size and peripheraloutline, the two plates being in registry or in alignment when pressedtogether. The lithium anode may also be deposited on the anode currentcollector 32 by vacuum deposition, electroplating or other conventionalmethods.

The open top of casing 12 housing the anode 26 and anode currentcollector 32 positioned therein, as shown in FIG. 2, is closed by a lid34 provided with a fill opening (not shown). Then, thehalogen-containing cathode material 36 is introduced into the casing 12through the fill opening provided in lid 34 such that the cathodematerial is in operative contact with the anode 26 and with the sides14, 16, bottom 22 and end walls 18, 20 of the conductive metal casing12, which serves as the cathode current collector. The cathode material36 preferably comprises a charge transfer complex of an organic materialand iodine, although any other cathode active material may be used thatis electronically conductive and contains available iodine for theelectrochemical reaction.

Charge transfer complexes are a well-known class of materials that havetwo components, one an electron donor, the other an electron acceptor,that form weakly bonded complexes that exhibit electronic conductivityhigher than either component. Suitable charge transfer complexes forthis invention consist of an organic donor component and iodine, theelectron acceptor, preferably has a conductivity of greater than about2.5×10⁻⁴ ohm/cm. The charge transfer complexes are in chemicalequilibrium with some small amount of free iodine that is available forelectrochemical reaction. These charge transfer complexes have a widerange of electronic conductivity. If the conductivity is low, thecurrent output will be comparatively low because of the high internalohmic resistance. Cathodes containing intimate mixtures of such lowconductivity complexes with powdered graphite or inert metal have highconductivities and can provide electrical discharge performancecomparable to cells using high conductivity complexes.

In particular, the cathode material 36 is prepared by heating theorganic material mixed with iodine to a temperature greater than thecrystallization temperature of iodine, for example about 300° F. Theamount of iodine should be greater than about 50 percent by weight ofthe resulting mixture so that enough iodine is available in the cathodematerial to provide sufficient conductivity for proper cell operation.The resulting mixture is a viscous, flowable substance, which ispreferably introduced into the cell casing 12 by flowing it through theabove mentioned fill opening in lid 34. When filling is completed, aclosure element 38, preferably also of stainless steel, or the like, iswelded to the lid 34 in the fill opening and a terminal lead 40 is spotwelded to closure, either before or after the closure element 38 iswelded to lid 34.

Suitable charge transfer complexes may be prepared using as organicdonor components polycyclic aromatic compounds, such as, for example,pyrene, perylene, anthracene, naphthalene, erythrosine, azulene andfluorene; organic polymers, such as, for example, polyethylene,polypropylene, polystyrene, polypyrrole, polyamides and polyvinyls; orheterocyclic compounds, containing nitrogen or sulfur, such as, forexample, phenothiazine, phenazine, 10-phenylphenophiozine, thianthrene,10-methylthiazinc and methalyineblue; and polymerized or polymerizablecompounds in which a heterocyclic nitrogen moiety is incorporated as aside chain or substituent, especially vinyl compounds and polymers, suchas poly-2-vinyl quinoline, poly-2-vinyl pyridine, poly-4-vinyl pyridine,poly-5-vinyl-2-methyl-pyridine and poly-N-vinyl carbazole. Theproportions of iodine to organic component can be varied over a widerange, although a high proportion of uncomplexed iodine in the cathodegenerally increases internal cell resistance. Other iodine containingcathodes that are electronically conductive may also be used, such asmixtures of iodine and carbon or graphite.

A lithium iodide electrolyte 42 is formed in situ by reaction of theiodine present in the cathode with the lithium anode. It is equallysatisfactory, and in some instances preferable, to form a film oflithium salt electrolyte on the anode surface abutting the cathode priorto cell assembly. That's done most conveniently by exposing the anodesurface to dry air or argon atmosphere containing halogen gas or vapor.It will be recognized that additional lithium iodide electrolyte isformed by the electrochemical reaction of the cell.

A strip or band of electrical insulating material 44 serves to insulateanode 26 from the metal lid 34 of casing 12 in a completed or assembledcell. An anode lead (not shown) extends from the anode current collector32 through a glass-to-metal seal serves an insulator and seal structure46 and becomes an anode terminal lead 48, which extends through lid 34.For a more detailed description of such an alkali metal-halogen cell,reference may be made to U.S. Pat. No. 4,401,736 issued Aug. 30, 1983entitled “Anode Assembly For Lithium Halogen Cell” and assigned to theassignee of the present invention, the disclosure of which is herebyincorporated by reference.

The above described exemplary alkali metal-halogen electrochemical cellhoused in the bead blasted casing according to the present inventionperforms as well as or better than a comparable cell having a casetreated by the more costly acid-cleaning and electro-polishing processesof the prior art.

The following example describes the manner and process of carrying outthe present invention in an electrochemical cell, and this example setsforth the best mode contemplated by the inventors of carrying out theinvention, but it is not to be construed as limiting.

Example

Lithium/iodine cells of case-positive configurations similar inconstruction to the exemplary alkali metal-halide cell 10 just describedwere used as test vehicles. The cells were constructed to deliver ratecapacities of 1.32 Ah. Stainless steel cases were conditioned using thethree methods previously discussed, conventional chemical etching,conventional electro-polishing and bead blasting according to thepresent invention. Three groups of cells were fabricated, group “A” inwhich the casings were bead blasted according to the present invention,a prior art group “B” in which the casings were electro-polished using asolution of about 20 volume percent perchloric acid and about 80 volumepercent acetic acid, and a prior art group “C” in which the casing weretreated using Diversey® chemical etchant.

After fabrication, all cells were preconditioned at 37° C. by dischargeunder 6.98K loads for a period of about 60 hours, followed by placementunder 100K loads for about 24 hours. Closed circuit voltage and 1 kHzinternal impedance readings were recorded throughout thispreconditioning period.

At beginning-of-life, alkali metal-halogen cells typically arecharacterized by high loaded voltages and low internal impedances. Asshown in Table 1, the cells comprising the bead blasted case surfaceaccording to the present invention exhibited electrical dischargecharacteristics equaling or exceeding those of cells housed in acidtreated or electro-polished cases.

TABLE I Final 100K Final 100K loaded loaded voltage, impedance, S/NGroup mv ohms 711 A 2,726 86 712 2,725 88 713 2,726 85 714 2,731 82 7152,727 84 716 2,725 85 717 2,726 90 718 2,718 97 719 2,719 100 720 2,72195 721 2,718 97 722 2,722 94 723 2,723 91 724 2,724 92 725 2,727 86 7262,723 93 727 2,726 88 728 2,726 83 729 2,725 89 730 2,724 92 731 2,72687 732 2,726 90 733 2,726 89 734 2,719 98 735 2,721 96 2,724 +/− 3  90+/− 5 686 B 2,694 94 687 2,708 94 688 2,693 96 689 2,688 92 690 2,698 93691 2,695 100 692 2,690 94 693 2,685 95 694 2,696 102 695 2,687 100 6962,700 97 697 2,687 102 698 2,682 94 699 2,699 90 700 2,697 89 701 2,68289 702 2,679 88 703 2,677 92 704 2,675 91 705 2,678 89 706 2,699 92 7072,700 85 708 2,704 87 709 2,702 89 710 2,707 94 2,692 +/− 10 95 +/− 5661 C 2,687 89 662 2,679 93 663 2,665 92 665 2,694 82 666 2,671 84 6672,670 91 668 2,669 92 669 2,679 87 670 2,687 84 671 2,657 92 672 2,65687 673 2,678 97 674 2,658 86 675 2,688 94 676 2,698 85 677 2,661 85 6782,673 87 679 2,699 88 680 2,684 88 681 2,683 90 682 2,653 91 683 2,67187 684 2,686 85 685 2,680 87  2676 +/− 13 88 +/− 4

The bead blasting process of the present invention is seen to havecaused the cathodic current collectors, i.e., the inner case surfaces,to perform as effectively as those which have been acid-treated orelectro-polished according to the prior art. High loaded cell voltage ismaintained and internal impedance is typically lowered for the presentinvention cells in comparison to those of a comparable chemistry housedin casings having their internal surfaces treated according to the priorart. As illustrated by the data above, the bead blasted cells not onlyhave a greater high loaded cell voltage output averaging about 2,724 mV,but also have the lowest standard deviation of about 3 mV. It is,therefore, believed that the case conditioning afforded by the beadblasting method of the present invention improves voltage outputperformance and manufacturability of alkali metal-halogenelectrochemical cells.

It is appreciated that various modifications to the inventive conceptsdescribed herein may be apparent to those skilled in the art withoutdeparting from the spirit and scope of the present invention defined bythe hereinafter appended claims.

What is claimed is:
 1. An electrochemical cell, comprising: a) a casingof an electrically conductive material; b) a lithium anode supported onan anode current collector housed inside the casing; c) a glass-to-metalseal supported by the casing and configured to electrically isolate theanode current collector from the casing; and d) a cathode comprising aniodine-containing material in electrochemical association with thelithium anode inside the casing, wherein the iodine-containing materialcontacts an inner surface of the casing serving as a cathode currentcollector, e) wherein, prior to contact with the iodine-containingmaterial, at least a portion of the inner surface of the casing ischaracterized as having been subjected to a pressurized stream of beads,f) wherein the cell has a rate capacity of about 1.32 Ah, and g)wherein, after fabrication, the cell is characterized as having beendischarged at 37° C. under a 6.98K load for a period of about 60 hours,followed by having been subjected to a 100K load for about 24 hours sothat the cell exhibits a final 100K loaded voltage of about 2,724 mV±3mV and a final 100K loaded impedance of 90±5 ohms.
 2. Theelectrochemical cell of claim 1, configured to discharge according tothe following reaction: 2Li+I₂→LiI, and having an open circuit voltageof from about 2.7 to 2.8 volts.
 3. The electrochemical cell of claim 1,wherein the cathode comprises a mixture of iodine and carbon orgraphite.
 4. The electrochemical cell of claim 1, wherein theiodine-containing material is characterized as having been filled intothe casing as a flowable substance.
 5. The electrochemical cell of claim1, wherein the casing comprises an electrically conductive materialselected from the group consisting of stainless steel, titanium, mildsteel, nickel plated steel, aluminum, and nickel cobalt alloys.
 6. Theelectrochemical cell of claim 1, wherein the glass-to-metal seal issupported in a lid comprising the casing.
 7. The electrochemical cell ofclaim 1, wherein the inner surface of the casing is characterized ashaving been subjected to the pressurized stream of beads from about 2seconds to about 10 seconds.
 8. The electrochemical cell of claim 1,wherein, prior to contact with the iodine-containing material, at leastthe portion of the inner surface of the casing is characterized ashaving been subjected to the pressurized stream of beads for about 2 toabout 10 seconds.
 9. The electrochemical cell of claim 1, wherein, priorto contact with the iodine-containing material, at least the portion ofthe inner surface of the casing is characterized as having beensubjected to the pressurized stream of beads at a pressure from about0.34 MPa (50 psi) to about 0.48 MPa (70 psi).
 10. The electrochemicalcell of claim 1, wherein, prior to contact with the iodine-containingmaterial, at least the portion of the inner surface of the casing ischaracterized as having been subjected to the pressurized stream ofbeads selected from the group consisting of metal beads, alumina beads,and glass beads.
 11. The electrochemical cell of claim 10, wherein theglass beads have a grain size from about 35 μm to about 65 μm, per MILSPEC “G”-9954A.
 12. The electrochemical cell of claim 1, wherein thecathode comprises a charge transfer complex and iodine.
 13. Theelectrochemical cell of claim 12, wherein the charge transfer complex isselected from the group consisting of pyrene, perylene, anthracene,naphthalene, erythrosine, azulene, fluorene, polyethylene,polypropylene, polystyrene, polypyrrole, polyamides, polyvinyls,phenothiazine, phenazine, 10-phenylphenophiozine, thianthrene,10-methylthiazinc, methalyineblue, poly-2-vinyl quinoline, poly-2-vinylpyridine, poly-4-vinyl pyridine, poly-5-vinyl-2-methyl-pyridine,poly-N-vinyl carbazole.
 14. The electrochemical cell of claim 12,wherein the charge transfer complex comprises an organic donor componentand an electron acceptor.
 15. The electrochemical cell of claim 14,wherein the electron acceptor has a conductivity greater than about2.5×10⁻⁴ ohm/cm.
 16. An electrochemical cell, comprising: a) a casing ofstainless steel; b) a lithium anode supported on an anode currentcollector comprised of nickel, the lithium anode being housed inside thecasing; c) a glass-to-metal seal supported by the casing, wherein theglass-to-metal seal is configured to electrically isolate the anodecurrent collector from the casing; and d) a cathode comprising aniodine-containing material in electrochemical association with thelithium anode inside the casing, wherein the iodine-containing materialcontacts an inner surface of the casing serving as a cathode currentcollector, e) wherein, prior to contact with the iodine-containingmaterial, at least a portion of the inner surface of the casing ischaracterized as having been subjected to a pressurized stream of beads,and f) wherein, after fabrication, the cell is characterized as havingbeen discharged at 37° C. under a 6.98K load for a period of about 60hours, followed by having been subjected to a 100K load for about 24hours so that the cell exhibits a final 100K loaded voltage of about2,724 mV±3 mV and a final 100K loaded impedance of 90±5 ohms.
 17. Theelectrochemical cell of claim 16 having a rate capacity of 1.32 Ah. 18.An electrochemical cell, comprising: a) a casing of stainless steel; b)a lithium anode supported on an anode current collector comprised ofnickel, the lithium anode being housed inside the casing; c) aglass-to-metal seal supported by the casing, wherein the glass-to-metalseal is configured to electrically isolate the anode current collectorfrom the casing; and d) a cathode comprising an iodine-containingmaterial in electrochemical association with the lithium anode insidethe casing, wherein the iodine-containing material contacts an innersurface of the casing serving as a cathode current collector, e)wherein, prior to contact with the iodine-containing material, at leasta portion of the inner surface of the casing is characterized as havingbeen subjected to a pressurized stream of glass beads having a grainsize from about 35 μm to about 65 μm, per MIL SPEC “G”-9954A at apressure from about 0.34 MPa (50 psi) to about 0.48 MPa (70 psi), and f)wherein, after fabrication, the cell is characterized as having beendischarged at 37° C. under a 6.98K load for a period of about 60 hours,followed by having been subjected to a 100K load for about 24 hours sothat the cell exhibits a final 100K loaded voltage of about 2,724 mV±3mV and a final 100K loaded impedance of 90±5 ohms.
 19. Theelectrochemical cell of claim 18 having a rate capacity of 1.32 Ah.